Broke drill bit off

[BruceP]

I was putting the canopy side skirts on today and broke a drill bit off in the rearmost hole of the skirt because it had to be drilled deeper to get through all the weld material at the junction of the side frame and the rear hoop. Any ideas how to get it out or how to attach short of drilling? The hole is 3/8" deep from the surface of the skirt. (You may notice I glued my canopy on which is why there is glue peeking out at the top of the skirt)

[lr172]

My opinion:

Assuming the drill bit did not penetrate the back side, I would just leave it. Fill the hole with epoxy/flox. If you feel that you need a screw there, drill a new hole nearby where it will work. You can also epoxy the skirt to the plexi there to hold it.

Because the canopy is glued, the plexi and aluminum can't really move much due to differential expansion. I really don't know how much flex/movement you can expect from your adhesive. I suppose there is some risk to the plexi from having a tight pin in there, but the risk seems less than the methods to get it out.

Because this is at a corner, any potential crack due to the tight pin has a good likelihood of propagating to an edge where it would be invisible and benign.

Larry

Don't leave it. You could fabricate a hole finder to drill from other side and knock it out.
Could even carefully measure to find other side.

[lr172]

I would not try to remove it without somehow loosening it. If you force the bit to move in any lateral direction, without relief, you run a SERIOUS risk of cracking the plexi. forcing the bit to move sideways causes something to give. Aluminum easily deforms, plexi cracks.

Proceed with caution here.

Larry

[lr172]

Originally Posted by paul mosher

Don't leave it. You could fabricate a hole finder to drill from other side and knock it out.
Could even carefully measure to find other side.

I would NOT try to knock something embedded in plexiglass out with force. If you read the archives, you will quickly learn that force and plexi do not mix in most situations. You don't know how the bit is hung up. It could be twisted out of alignment, meaning the sharp edge of the flutes is grabbing the plexi. Tapping that bit, if that were the case, would invite a crack.

Larry

Use a small drill bit to locate it. Push it out. it is obviously below the plexi, he glued his canopy on. It's the holes that secure the skirt not plexi.
If this is a 7 I believe the plans call out to locate hole to avoid the weld.

Also why are you installing screws when all the holes are not drilled?

[lr172]

Originally Posted by paul mosher

Use a small drill bit to locate it. Push it out. it is obviously below the plexi, he glued his canopy on. It's the holes that secure the skirt not plexi.
If this is a 7 I believe the plans call out to locate hole to avoid the weld.

I stand corrected. I guess I didn't look that close to the picture and assumed they went through the plexi like non-glued canopies.

[BruceP]

I appreciate the comments. Paul, I am not installing any screws, I was trying to get the hole deep enough to pull the rivet.

[HIIFLY]

I use a soldering iron / gun to put holes in plexiglas ,for mounting screws in windshields , could you this method to heat up the broken drill bit for removal ? Just a thought ,